Influence of Excavation of Complex Foundation Pit on Surrounding Environment

In order to study the deformation of the complex foundation pit, based on an engineering example, the influence of the excavation of foundation pit on adjacent buildings with different supporting structures is analyzed by the finite element software MIDAS GTS/NX especially for the fragile soil. The supporting structure is simplified by the principle of equivalent flexural rigidity, and the model of theoretical calculation with better accuracy and efficiency is established. The results show that the northern foundation pit with combined support structure of double row pile with inclined bracing and pile anchor first carried out by stratified excavation has great influence on the deformation of the building. When the foundation pit is excavated to -2.80m, the rate of settlement deformation and the rate of horizontal deformation of the retaining structure are larger. After the excavation of the northern foundation pit, the settlement of the building has reached 4/5 of the total settlement. The later southern foundation pit with the supporting structures of inner support has little influence on the settlement deformation of adjacent buildings. In this paper, the effects of deformation of the two supporting structures are compared and analyzed in order to provide technical reference for the similar engineering of foundation pit about selection and construction of supporting structure.